We are sufficient in Christ. We need nothing else. Such a statement is foreign to most persons today (believers and nonbelievers). In an age of psychology, charmismania, cultural accommodation, etc. it seems foreign to think that believers have every spiritual resource necessary in Christ alone.
That's the argument of John MacArthur in his book, "Our Sufficiency in Christ." To him, to many Christians are going outside the Biblical worldview and outside of Christ to find fulfillment, answers, help, assurance, salvation, and hope. MacArthur is calling us all back to the simple truth that we have all that we need in Christ and in Christ alone.
The book begins by looking at the dangers of modern psychology. MacArthur is not anti-psychology. He does, however, have concerns. MacArthur lays out that the believer can find the answers to their problems solely in Scripture. This does not mean that MacArthur finds psychology unnecessary, but that it has lead to all-out assault against the sufficiency of Scripture and thus, the sufficiency of Christ.
Although MacArthur is not surprised that the culture has abandoned the belief in the sufficiency of Christ, he is shocked that Christians are so easily led astray from it. It says something of the faith and belief of Christians whenever they begin to go elsewhere for answers and for truth.
Perhaps the most helpful section of this book, at least for me, regards his discussion on sanctification. He begins by surveying two major extremes: pietism and quietism. Each movement focuses primarily on one aspect of sanctification. Pietism emphasizes the believers roll in sanctification. Quietism emphasizes God's roll in our sanctification. MacArthur lays out the foundation of both our and God's roll in sanctification. Both are involved in sanctifying the believer.
This was perhaps the best, and yet somewhat brief, discussion on the doctrine of sanctification. It was nice to step back and look at sanctification and what the Bible says about it and then see the specifics.
Overall, I recommend this book, as well as with his other books. MacArthur cares about what the text says and nothing else. He is unwilling to compromise. MacArthur, in my opinion, is the best Bible teacher of our day and any book, article, or sermon we can get your hands on will be bring fruit to your soul.